I have spoken to a number of people about this ( mostly non-Buddhist & with 1 Buddhist) , whom think she is emotionally manipulating me , putting all the blame onto me for her actions and spending habits; none of them think I should pay her any money for her decision making, and that it is 'out of line' for her to ask. I sent some money that I did forget about, something concrete , but the rest seemed very arbitrary and it was a fairly large sum for me ($3000) - I have been saving for my first overseas trip the last three years, and obviously I am attached to this

So I guess, What I'm after is what you, Buddhist practitioners would do.... How do I balance wanting to give, without being taken advantage of? I have had to block her at the moment as the emotional abuse (everyday 50-100 messages) was starting to affect me .

So...someone you haven't been in a relationship with for three years turns up and harasses you for thousands of dollars because she paid for some takeout food?

Clearly she's not going to get any money from you by legal means. I would ignore her completely, just don't engage, except in one circumstance. If you really did something terrrible to her, some lasting evil deed that can never see the light of day and for which an apology just isn't enough. I'm not talking here about failure to split a bill - I mean burning her house down, killing her dog, etc. Didn't do any of those? Then just say no and get on with your life. The Buddhist perspective is not only informed by compassion, it also requires wisdom.